Wednesday 14 August 2013

Immobiliser

Everything back together for a test  - the circuit I have been adding was a simple immobiliser which cuts some circuits unless another electronic key is used to disable it. It is auto arming, as soon as the ignition is turned off it arms itself and has the ubiquitous flashing led to show its presence:


The intention is to guard against simple hot wiring of the ignition. If someone starts to take the bonnet off or get in the back of the fusebox (good luck with that rats nest), or simply tow the car then all bets are off.

Hopefully though it will stop a passing opportunist joyride attempt and give me a little more protection than the stock Ford ignition key barrel.

I'm not posting installation details for obvious reasons.

Fuse and Relay identification

Back from summer holidays;

Theres no circuit diagram, even for the stock GBS Zero loom, that I know of - so to add my couple of circuits & while the fuse box was disassembled I took some time to trace out fuse and relay functions. The relay functions were cribbed from a picture on DC Tough's pictures then confirmed with circuit testing:

My fuse box is mounted upside down with fuses on top, so flip this if using it on the standard layout. The lighting circuits are not of interest so I didn't fully trace everything.

Top 3 rows of fuses are permanent live feed, the bottom row controlled by the Aux relay. All 4 left hand columns are fed by a bus bar so is straightforward to use some of the spare slots.

This is the ECU power arrangement, pin 11 is driven directly from the ignition switch, pin 28 via the ECU relay which in itself is also controlled by the ECU from Pin 4:

Touch wood everything will still work when I put it back together!

Upadate - Some re-identification and extra circuits added later.